<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			ul,
			li,
			div {
				-moz-box-sizing: border-box;
				/* firefox */
				-webkit-box-sizing: border-box;
				/* chrome safari */
				-ms-box-sizing: border-box;
				/* IE8以下 */
				-o-box-sizing: border-box;
				/* presto opera */
			}

			.content-box {
				-moz-box-sizing: content-box;
				/* firefox */
				-webkit-box-sizing: content-box;
				/* chrome safari */
				-ms-box-sizing: content-box;
				/* IE8以下 */
				-o-box-sizing: content-box;
				/* presto opera */
				/* 解开方法 */
			}
		</style>
	</head>
	<body>
		<div class="box"></div>
	</body>
</html>
